@article{9305, abstract = {Copper chalcogenides are outstanding thermoelectric materials for applications in the medium-high temperature range. Among different chalcogenides, while Cu2−xSe is characterized by higher thermoelectric figures of merit, Cu2−xS provides advantages in terms of low cost and element abundance. In the present work, we investigate the effect of different dopants to enhance the Cu2−xS performance and also its thermal stability. Among the tested options, Pb-doped Cu2−xS shows the highest improvement in stability against sulfur volatilization. Additionally, Pb incorporation allows tuning charge carrier concentration, which enables a significant improvement of the power factor. We demonstrate here that the introduction of an optimal additive amount of just 0.3% results in a threefold increase of the power factor in the middle-temperature range (500–800 K) and a record dimensionless thermoelectric figure of merit above 2 at 880 K.}, author = {Zhang, Yu and Xing, Congcong and Liu, Yu and Spadaro, Maria Chiara and Wang, Xiang and Li, Mengyao and Xiao, Ke and Zhang, Ting and Guardia, Pablo and Lim, Khak Ho and Moghaddam, Ahmad Ostovari and Llorca, Jordi and Arbiol, Jordi and Ibáñez, Maria and Cabot, Andreu}, issn = {2211-2855}, journal = {Nano Energy}, number = {7}, publisher = {Elsevier}, title = {{Doping-mediated stabilization of copper vacancies to promote thermoelectric properties of Cu2-xS}}, doi = {10.1016/j.nanoen.2021.105991}, volume = {85}, year = {2021}, } @article{9307, abstract = {We establish finite time extinction with probability one for weak solutions of the Cauchy–Dirichlet problem for the 1D stochastic porous medium equation with Stratonovich transport noise and compactly supported smooth initial datum. Heuristically, this is expected to hold because Brownian motion has average spread rate O(t12) whereas the support of solutions to the deterministic PME grows only with rate O(t1m+1). The rigorous proof relies on a contraction principle up to time-dependent shift for Wong–Zakai type approximations, the transformation to a deterministic PME with two copies of a Brownian path as the lateral boundary, and techniques from the theory of viscosity solutions.}, author = {Hensel, Sebastian}, issn = {2194-041X}, journal = {Stochastics and Partial Differential Equations: Analysis and Computations}, pages = {892–939}, publisher = {Springer Nature}, title = {{Finite time extinction for the 1D stochastic porous medium equation with transport noise}}, doi = {10.1007/s40072-021-00188-9}, volume = {9}, year = {2021}, } @article{9315, abstract = {We consider inertial iteration methods for Fermat–Weber location problem and primal–dual three-operator splitting in real Hilbert spaces. To do these, we first obtain weak convergence analysis and nonasymptotic O(1/n) convergence rate of the inertial Krasnoselskii–Mann iteration for fixed point of nonexpansive operators in infinite dimensional real Hilbert spaces under some seemingly easy to implement conditions on the iterative parameters. One of our contributions is that the convergence analysis and rate of convergence results are obtained using conditions which appear not complicated and restrictive as assumed in other previous related results in the literature. We then show that Fermat–Weber location problem and primal–dual three-operator splitting are special cases of fixed point problem of nonexpansive mapping and consequently obtain the convergence analysis of inertial iteration methods for Fermat–Weber location problem and primal–dual three-operator splitting in real Hilbert spaces. Some numerical implementations are drawn from primal–dual three-operator splitting to support the theoretical analysis.}, author = {Iyiola, Olaniyi S. and Shehu, Yekini}, issn = {1420-9012}, journal = {Results in Mathematics}, number = {2}, publisher = {Springer Nature}, title = {{New convergence results for inertial Krasnoselskii–Mann iterations in Hilbert spaces with applications}}, doi = {10.1007/s00025-021-01381-x}, volume = {76}, year = {2021}, } @article{9316, abstract = {Embryo morphogenesis is impacted by dynamic changes in tissue material properties, which have been proposed to occur via processes akin to phase transitions (PTs). Here, we show that rigidity percolation provides a simple and robust theoretical framework to predict material/structural PTs of embryonic tissues from local cell connectivity. By using percolation theory, combined with directly monitoring dynamic changes in tissue rheology and cell contact mechanics, we demonstrate that the zebrafish blastoderm undergoes a genuine rigidity PT, brought about by a small reduction in adhesion-dependent cell connectivity below a critical value. We quantitatively predict and experimentally verify hallmarks of PTs, including power-law exponents and associated discontinuities of macroscopic observables. Finally, we show that this uniform PT depends on blastoderm cells undergoing meta-synchronous divisions causing random and, consequently, uniform changes in cell connectivity. Collectively, our theoretical and experimental findings reveal the structural basis of material PTs in an organismal context.}, author = {Petridou, Nicoletta and Corominas-Murtra, Bernat and Heisenberg, Carl-Philipp J and Hannezo, Edouard B}, issn = {1097-4172}, journal = {Cell}, number = {7}, pages = {1914--1928.e19}, publisher = {Elsevier}, title = {{Rigidity percolation uncovers a structural basis for embryonic tissue phase transitions}}, doi = {10.1016/j.cell.2021.02.017}, volume = {184}, year = {2021}, } @article{9317, abstract = {Given a locally finite X⊆Rd and a radius r≥0, the k-fold cover of X and r consists of all points in Rd that have k or more points of X within distance r. We consider two filtrations—one in scale obtained by fixing k and increasing r, and the other in depth obtained by fixing r and decreasing k—and we compute the persistence diagrams of both. While standard methods suffice for the filtration in scale, we need novel geometric and topological concepts for the filtration in depth. In particular, we introduce a rhomboid tiling in Rd+1 whose horizontal integer slices are the order-k Delaunay mosaics of X, and construct a zigzag module of Delaunay mosaics that is isomorphic to the persistence module of the multi-covers.}, author = {Edelsbrunner, Herbert and Osang, Georg F}, issn = {1432-0444}, journal = {Discrete and Computational Geometry}, pages = {1296–1313}, publisher = {Springer Nature}, title = {{The multi-cover persistence of Euclidean balls}}, doi = {10.1007/s00454-021-00281-9}, volume = {65}, year = {2021}, } @misc{9323, abstract = {This .zip File contains the data for figures presented in the main text and supplementary material of "A singlet triplet hole spin qubit in planar Ge" by D. Jirovec, et. al. The measurements were done using Labber Software and the data is stored in the hdf5 file format. The files can be opened using either the Labber Log Browser (https://labber.org/overview/) or Labber Python API (http://labber.org/online-doc/api/LogFile.html). A single file is acquired with QCodes and features the corresponding data type. XRD data are in .dat format and a code to open the data is provided. The code for simulations is as well provided in Python.}, author = {Jirovec, Daniel}, publisher = {Institute of Science and Technology Austria}, title = {{Research data for "A singlet-triplet hole spin qubit planar Ge"}}, doi = {10.15479/AT:ISTA:9323}, year = {2021}, } @article{9329, abstract = {Background: To understand information coding in single neurons, it is necessary to analyze subthreshold synaptic events, action potentials (APs), and their interrelation in different behavioral states. However, detecting excitatory postsynaptic potentials (EPSPs) or currents (EPSCs) in behaving animals remains challenging, because of unfavorable signal-to-noise ratio, high frequency, fluctuating amplitude, and variable time course of synaptic events. New method: We developed a method for synaptic event detection, termed MOD (Machine-learning Optimal-filtering Detection-procedure), which combines concepts of supervised machine learning and optimal Wiener filtering. Experts were asked to manually score short epochs of data. The algorithm was trained to obtain the optimal filter coefficients of a Wiener filter and the optimal detection threshold. Scored and unscored data were then processed with the optimal filter, and events were detected as peaks above threshold. Results: We challenged MOD with EPSP traces in vivo in mice during spatial navigation and EPSC traces in vitro in slices under conditions of enhanced transmitter release. The area under the curve (AUC) of the receiver operating characteristics (ROC) curve was, on average, 0.894 for in vivo and 0.969 for in vitro data sets, indicating high detection accuracy and efficiency. Comparison with existing methods: When benchmarked using a (1 − AUC)−1 metric, MOD outperformed previous methods (template-fit, deconvolution, and Bayesian methods) by an average factor of 3.13 for in vivo data sets, but showed comparable (template-fit, deconvolution) or higher (Bayesian) computational efficacy. Conclusions: MOD may become an important new tool for large-scale, real-time analysis of synaptic activity.}, author = {Zhang, Xiaomin and Schlögl, Alois and Vandael, David H and Jonas, Peter M}, issn = {1872-678X}, journal = {Journal of Neuroscience Methods}, number = {6}, publisher = {Elsevier}, title = {{MOD: A novel machine-learning optimal-filtering method for accurate and efficient detection of subthreshold synaptic events in vivo}}, doi = {10.1016/j.jneumeth.2021.109125}, volume = {357}, year = {2021}, } @article{9330, abstract = {In nerve cells the genes encoding for α2δ subunits of voltage-gated calcium channels have been linked to synaptic functions and neurological disease. Here we show that α2δ subunits are essential for the formation and organization of glutamatergic synapses. Using a cellular α2δ subunit triple-knockout/knockdown model, we demonstrate a failure in presynaptic differentiation evidenced by defective presynaptic calcium channel clustering and calcium influx, smaller presynaptic active zones, and a strongly reduced accumulation of presynaptic vesicle-associated proteins (synapsin and vGLUT). The presynaptic defect is associated with the downscaling of postsynaptic AMPA receptors and the postsynaptic density. The role of α2δ isoforms as synaptic organizers is highly redundant, as each individual α2δ isoform can rescue presynaptic calcium channel trafficking and expression of synaptic proteins. Moreover, α2δ-2 and α2δ-3 with mutated metal ion-dependent adhesion sites can fully rescue presynaptic synapsin expression but only partially calcium channel trafficking, suggesting that the regulatory role of α2δ subunits is independent from its role as a calcium channel subunit. Our findings influence the current view on excitatory synapse formation. First, our study suggests that postsynaptic differentiation is secondary to presynaptic differentiation. Second, the dependence of presynaptic differentiation on α2δ implicates α2δ subunits as potential nucleation points for the organization of synapses. Finally, our results suggest that α2δ subunits act as transsynaptic organizers of glutamatergic synapses, thereby aligning the synaptic active zone with the postsynaptic density.}, author = {Schöpf, Clemens L. and Ablinger, Cornelia and Geisler, Stefanie M. and Stanika, Ruslan I. and Campiglio, Marta and Kaufmann, Walter and Nimmervoll, Benedikt and Schlick, Bettina and Brockhaus, Johannes and Missler, Markus and Shigemoto, Ryuichi and Obermair, Gerald J.}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {14}, publisher = {National Academy of Sciences}, title = {{Presynaptic α2δ subunits are key organizers of glutamatergic synapses}}, doi = {10.1073/pnas.1920827118}, volume = {118}, year = {2021}, } @article{9331, abstract = {Quantum entanglement has been generated and verified in cold-atom experiments and used to make atom-interferometric measurements below the shot-noise limit. However, current state-of-the-art cold-atom devices exploit separable (i.e., unentangled) atomic states. This perspective piece asks the question: can entanglement usefully improve cold-atom sensors, in the sense that it gives new sensing capabilities unachievable with current state-of-the-art devices? We briefly review the state-of-the-art in precision cold-atom sensing, focusing on clocks and inertial sensors, identifying the potential benefits entanglement could bring to these devices, and the challenges that need to be overcome to realize these benefits. We survey demonstrated methods of generating metrologically useful entanglement in cold-atom systems, note their relative strengths and weaknesses, and assess their prospects for near-to-medium term quantum-enhanced cold-atom sensing.}, author = {Szigeti, Stuart S. and Hosten, Onur and Haine, Simon A.}, issn = {0003-6951}, journal = {Applied Physics Letters}, number = {14}, publisher = {AIP Publishing}, title = {{Improving cold-atom sensors with quantum entanglement: Prospects and challenges}}, doi = {10.1063/5.0050235}, volume = {118}, year = {2021}, } @article{9332, abstract = {Lateral root (LR) formation is an example of a plant post-embryonic organogenesis event. LRs are issued from non-dividing cells entering consecutive steps of formative divisions, proliferation and elongation. The chromatin remodeling protein PICKLE (PKL) negatively regulates auxin-mediated LR formation through a mechanism that is not yet known. Here we show that PKL interacts with RETINOBLASTOMA-RELATED 1 (RBR1) to repress the LATERAL ORGAN BOUNDARIES-DOMAIN 16 (LBD16) promoter activity. Since LBD16 function is required for the formative division of LR founder cells, repression mediated by the PKL–RBR1 complex negatively regulates formative division and LR formation. Inhibition of LR formation by PKL–RBR1 is counteracted by auxin, indicating that, in addition to auxin-mediated transcriptional responses, the fine-tuned process of LR formation is also controlled at the chromatin level in an auxin-signaling dependent manner.}, author = {Ötvös, Krisztina and Miskolczi, Pál and Marhavý, Peter and Cruz-Ramírez, Alfredo and Benková, Eva and Robert, Stéphanie and Bakó, László}, issn = {1422-0067}, journal = {International Journal of Molecular Sciences}, number = {8}, publisher = {MDPI}, title = {{Pickle recruits retinoblastoma related 1 to control lateral root formation in arabidopsis}}, doi = {10.3390/ijms22083862}, volume = {22}, year = {2021}, } @article{9335, abstract = {Various degenerate diffusion equations exhibit a waiting time phenomenon: depending on the “flatness” of the compactly supported initial datum at the boundary of the support, the support of the solution may not expand for a certain amount of time. We show that this phenomenon is captured by particular Lagrangian discretizations of the porous medium and the thin film equations, and we obtain sufficient criteria for the occurrence of waiting times that are consistent with the known ones for the original PDEs. For the spatially discrete solution, the waiting time phenomenon refers to a deviation of the edge of support from its original position by a quantity comparable to the mesh width, over a mesh-independent time interval. Our proof is based on estimates on the fluid velocity in Lagrangian coordinates. Combining weighted entropy estimates with an iteration technique à la Stampacchia leads to upper bounds on free boundary propagation. Numerical simulations show that the phenomenon is already clearly visible for relatively coarse discretizations.}, author = {Fischer, Julian L and Matthes, Daniel}, issn = {0036-1429}, journal = {SIAM Journal on Numerical Analysis}, number = {1}, pages = {60--87}, publisher = {Society for Industrial and Applied Mathematics}, title = {{The waiting time phenomenon in spatially discretized porous medium and thin film equations}}, doi = {10.1137/19M1300017}, volume = {59}, year = {2021}, } @article{9348, abstract = {We consider the stochastic quantization of a quartic double-well energy functional in the semiclassical regime and derive optimal asymptotics for the exponentially small splitting of the ground state energy. Our result provides an infinite-dimensional version of some sharp tunneling estimates known in finite dimensions for semiclassical Witten Laplacians in degree zero. From a stochastic point of view it proves that the L2 spectral gap of the stochastic one-dimensional Allen-Cahn equation in finite volume satisfies a Kramers-type formula in the limit of vanishing noise. We work with finite-dimensional lattice approximations and establish semiclassical estimates which are uniform in the dimension. Our key estimate shows that the constant separating the two exponentially small eigenvalues from the rest of the spectrum can be taken independently of the dimension.}, author = {Brooks, Morris and Di Gesù, Giacomo}, issn = {1096-0783}, journal = {Journal of Functional Analysis}, number = {3}, publisher = {Elsevier}, title = {{Sharp tunneling estimates for a double-well model in infinite dimension}}, doi = {10.1016/j.jfa.2021.109029}, volume = {281}, year = {2021}, } @article{9351, abstract = {We consider the many-body quantum evolution of a factorized initial data, in the mean-field regime. We show that fluctuations around the limiting Hartree dynamics satisfy large deviation estimates that are consistent with central limit theorems that have been established in the last years. }, author = {Kirkpatrick, Kay and Rademacher, Simone Anna Elvira and Schlein, Benjamin}, issn = {1424-0637}, journal = {Annales Henri Poincare}, pages = {2595--2618}, publisher = {Springer Nature}, title = {{A large deviation principle in many-body quantum dynamics}}, doi = {10.1007/s00023-021-01044-1}, volume = {22}, year = {2021}, } @article{9352, abstract = {This paper provides an a priori error analysis of a localized orthogonal decomposition method for the numerical stochastic homogenization of a model random diffusion problem. If the uniformly elliptic and bounded random coefficient field of the model problem is stationary and satisfies a quantitative decorrelation assumption in the form of the spectral gap inequality, then the expected $L^2$ error of the method can be estimated, up to logarithmic factors, by $H+(\varepsilon/H)^{d/2}$, $\varepsilon$ being the small correlation length of the random coefficient and $H$ the width of the coarse finite element mesh that determines the spatial resolution. The proof bridges recent results of numerical homogenization and quantitative stochastic homogenization.}, author = {Fischer, Julian L and Gallistl, Dietmar and Peterseim, Dietmar}, issn = {0036-1429}, journal = {SIAM Journal on Numerical Analysis}, number = {2}, pages = {660--674}, publisher = {Society for Industrial and Applied Mathematics}, title = {{A priori error analysis of a numerical stochastic homogenization method}}, doi = {10.1137/19M1308992}, volume = {59}, year = {2021}, } @article{9359, abstract = {We prove that the factorization homologies of a scheme with coefficients in truncated polynomial algebras compute the cohomologies of its generalized configuration spaces. Using Koszul duality between commutative algebras and Lie algebras, we obtain new expressions for the cohomologies of the latter. As a consequence, we obtain a uniform and conceptual approach for treating homological stability, homological densities, and arithmetic densities of generalized configuration spaces. Our results categorify, generalize, and in fact provide a conceptual understanding of the coincidences appearing in the work of Farb--Wolfson--Wood. Our computation of the stable homological densities also yields rational homotopy types, answering a question posed by Vakil--Wood. Our approach hinges on the study of homological stability of cohomological Chevalley complexes, which is of independent interest. }, author = {Ho, Quoc P}, issn = {1364-0380}, journal = {Geometry & Topology}, keywords = {Generalized configuration spaces, homological stability, homological densities, chiral algebras, chiral homology, factorization algebras, Koszul duality, Ran space}, number = {2}, pages = {813--912}, publisher = {Mathematical Sciences Publishers}, title = {{Homological stability and densities of generalized configuration spaces}}, doi = {10.2140/gt.2021.25.813}, volume = {25}, year = {2021}, } @article{9368, abstract = {The quality control system for messenger RNA (mRNA) is fundamental for cellular activities in eukaryotes. To elucidate the molecular mechanism of 3'-Phosphoinositide-Dependent Protein Kinase1 (PDK1), a master regulator that is essential throughout eukaryotic growth and development, we employed a forward genetic approach to screen for suppressors of the loss-of-function T-DNA insertion double mutant pdk1.1 pdk1.2 in Arabidopsis thaliana. Notably, the severe growth attenuation of pdk1.1 pdk1.2 was rescued by sop21 (suppressor of pdk1.1 pdk1.2), which harbours a loss-of-function mutation in PELOTA1 (PEL1). PEL1 is a homologue of mammalian PELOTA and yeast (Saccharomyces cerevisiae) DOM34p, which each form a heterodimeric complex with the GTPase HBS1 (HSP70 SUBFAMILY B SUPPRESSOR1, also called SUPERKILLER PROTEIN7, SKI7), a protein that is responsible for ribosomal rescue and thereby assures the quality and fidelity of mRNA molecules during translation. Genetic analysis further revealed that a dysfunctional PEL1-HBS1 complex failed to degrade the T-DNA-disrupted PDK1 transcripts, which were truncated but functional, and thus rescued the growth and developmental defects of pdk1.1 pdk1.2. Our studies demonstrated the functionality of a homologous PELOTA-HBS1 complex and identified its essential regulatory role in plants, providing insights into the mechanism of mRNA quality control.}, author = {Kong, W and Tan, Shutang and Zhao, Q and Lin, DL and Xu, ZH and Friml, Jiří and Xue, HW}, issn = {1532-2548}, journal = {Plant Physiology}, number = {4}, pages = {2003--2020}, publisher = {American Society of Plant Biologists}, title = {{mRNA surveillance complex PELOTA-HBS1 eegulates phosphoinositide-sependent protein kinase1 and plant growth}}, doi = {10.1093/plphys/kiab199}, volume = {186}, year = {2021}, } @article{9374, abstract = {If there are no constraints on the process of speciation, then the number of species might be expected to match the number of available niches and this number might be indefinitely large. One possible constraint is the opportunity for allopatric divergence. In 1981, Felsenstein used a simple and elegant model to ask if there might also be genetic constraints. He showed that progress towards speciation could be described by the build‐up of linkage disequilibrium among divergently selected loci and between these loci and those contributing to other forms of reproductive isolation. Therefore, speciation is opposed by recombination, because it tends to break down linkage disequilibria. Felsenstein then introduced a crucial distinction between “two‐allele” models, which are subject to this effect, and “one‐allele” models, which are free from the recombination constraint. These fundamentally important insights have been the foundation for both empirical and theoretical studies of speciation ever since.}, author = {Butlin, Roger K. and Servedio, Maria R. and Smadja, Carole M. and Bank, Claudia and Barton, Nicholas H and Flaxman, Samuel M. and Giraud, Tatiana and Hopkins, Robin and Larson, Erica L. and Maan, Martine E. and Meier, Joana and Merrill, Richard and Noor, Mohamed A. F. and Ortiz‐Barrientos, Daniel and Qvarnström, Anna}, issn = {1558-5646}, journal = {Evolution}, keywords = {Genetics, Ecology, Evolution, Behavior and Systematics, General Agricultural and Biological Sciences}, number = {5}, pages = {978--988}, publisher = {Wiley}, title = {{Homage to Felsenstein 1981, or why are there so few/many species?}}, doi = {10.1111/evo.14235}, volume = {75}, year = {2021}, } @article{9375, abstract = {Genetic variation segregates as linked sets of variants, or haplotypes. Haplotypes and linkage are central to genetics and underpin virtually all genetic and selection analysis. And yet, genomic data often lack haplotype information, due to constraints in sequencing technologies. Here we present “haplotagging”, a simple, low-cost linked-read sequencing technique that allows sequencing of hundreds of individuals while retaining linkage information. We apply haplotagging to construct megabase-size haplotypes for over 600 individual butterflies (Heliconius erato and H. melpomene), which form overlapping hybrid zones across an elevational gradient in Ecuador. Haplotagging identifies loci controlling distinctive high- and lowland wing color patterns. Divergent haplotypes are found at the same major loci in both species, while chromosome rearrangements show no parallelism. Remarkably, in both species the geographic clines for the major wing pattern loci are displaced by 18 km, leading to the rise of a novel hybrid morph in the centre of the hybrid zone. We propose that shared warning signalling (Müllerian mimicry) may couple the cline shifts seen in both species, and facilitate the parallel co-emergence of a novel hybrid morph in both co-mimetic species. Our results show the power of efficient haplotyping methods when combined with large-scale sequencing data from natural populations.}, author = {Meier, Joana I. and Salazar, Patricio A. and Kučka, Marek and Davies, Robert William and Dréau, Andreea and Aldás, Ismael and Power, Olivia Box and Nadeau, Nicola J. and Bridle, Jon R. and Rolian, Campbell and Barton, Nicholas H and McMillan, W. Owen and Jiggins, Chris D. and Chan, Yingguang Frank}, issn = {0027-8424}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {25}, publisher = {National Academy of Sciences}, title = {{Haplotype tagging reveals parallel formation of hybrid races in two butterfly species}}, doi = {10.1073/pnas.2015005118}, volume = {118}, year = {2021}, } @article{9376, abstract = {This paper presents a method for designing planar multistable compliant structures. Given a sequence of desired stable states and the corresponding poses of the structure, we identify the topology and geometric realization of a mechanism—consisting of bars and joints—that is able to physically reproduce the desired multistable behavior. In order to solve this problem efficiently, we build on insights from minimally rigid graph theory to identify simple but effective topologies for the mechanism. We then optimize its geometric parameters, such as joint positions and bar lengths, to obtain correct transitions between the given poses. Simultaneously, we ensure adequate stability of each pose based on an effective approximate error metric related to the elastic energy Hessian of the bars in the mechanism. As demonstrated by our results, we obtain functional multistable mechanisms of manageable complexity that can be fabricated using 3D printing. Further, we evaluated the effectiveness of our method on a large number of examples in the simulation and fabricated several physical prototypes.}, author = {Zhang, Ran and Auzinger, Thomas and Bickel, Bernd}, issn = {1557-7368}, journal = {ACM Transactions on Graphics}, keywords = {multistability, mechanism, computational design, rigidity}, number = {5}, publisher = {Association for Computing Machinery}, title = {{Computational design of planar multistable compliant structures}}, doi = {10.1145/3453477}, volume = {40}, year = {2021}, } @article{9379, abstract = {When B cells encounter membrane-bound antigens, the formation and coalescence of B cell antigen receptor (BCR) microclusters amplifies BCR signaling. The ability of B cells to probe the surface of antigen-presenting cells (APCs) and respond to APC-bound antigens requires remodeling of the actin cytoskeleton. Initial BCR signaling stimulates actin-related protein (Arp) 2/3 complex-dependent actin polymerization, which drives B cell spreading as well as the centripetal movement and coalescence of BCR microclusters at the B cell-APC synapse. Sustained actin polymerization depends on concomitant actin filament depolymerization, which enables the recycling of actin monomers and Arp2/3 complexes. Cofilin-mediated severing of actin filaments is a rate-limiting step in the morphological changes that occur during immune synapse formation. Hence, regulators of cofilin activity such as WD repeat-containing protein 1 (Wdr1), LIM domain kinase (LIMK), and coactosin-like 1 (Cotl1) may also be essential for actin-dependent processes in B cells. Wdr1 enhances cofilin-mediated actin disassembly. Conversely, Cotl1 competes with cofilin for binding to actin and LIMK phosphorylates cofilin and prevents it from binding to actin filaments. We now show that Wdr1 and LIMK have distinct roles in BCR-induced assembly of the peripheral actin structures that drive B cell spreading, and that cofilin, Wdr1, and LIMK all contribute to the actin-dependent amplification of BCR signaling at the immune synapse. Depleting Cotl1 had no effect on these processes. Thus, the Wdr1-LIMK-cofilin axis is critical for BCR-induced actin remodeling and for B cell responses to APC-bound antigens.}, author = {Bolger-Munro, Madison and Choi, Kate and Cheung, Faith and Liu, Yi Tian and Dang-Lawson, May and Deretic, Nikola and Keane, Connor and Gold, Michael R.}, issn = {2296-634X}, journal = {Frontiers in Cell and Developmental Biology}, keywords = {B cell, actin, immune synapse, cell spreading, cofilin, WDR1 (AIP1), LIM domain kinase, B cell receptor (BCR)}, publisher = {Frontiers Media}, title = {{The Wdr1-LIMK-Cofilin axis controls B cell antigen receptor-induced actin remodeling and signaling at the immune synapse}}, doi = {10.3389/fcell.2021.649433}, volume = {9}, year = {2021}, }